2061465661 has 4 divisors (see below), whose sum is σ = 2080378300. Its totient is φ = 2042553024.

The previous prime is 2061465641. The next prime is 2061465719. The reversal of 2061465661 is 1665641602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1665641602 = 2 ⋅832820801.

It can be written as a sum of positive squares in 2 ways, for example, as 1161105625 + 900360036 = 34075^2 + 30006^2 .

It is a cyclic number.

It is not a de Polignac number, because 2061465661 - 2¹³ = 2061457469 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2061465661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2061465641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9456156 + ... + 9456373.

It is an arithmetic number, because the mean of its divisors is an integer number (520094575).

Almost surely, 2^2061465661 is an apocalyptic number.

It is an amenable number.

2061465661 is a deficient number, since it is larger than the sum of its proper divisors (18912639).

2061465661 is a wasteful number, since it uses less digits than its factorization.

2061465661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18912638.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 2061465661 is about 45403.3661857797. The cubic root of 2061465661 is about 1272.6980195489.

The spelling of 2061465661 in words is "two billion, sixty-one million, four hundred sixty-five thousand, six hundred sixty-one".